When I noticed them in the dealers tank they were labeled as
minnows. Considering the fact that the males had a rather large
gonopodium they couldn’t be any species that I recognized as a
minnow. As usual, I was intrigued by the identity of a fish I had
never seen before. What species could they be? I narrowed it down to
either genus Poecilia or Poeciliopsis on the basis of general body
shape. The species determination would have to wait until I could look
it up in Lothar Wiscanth’s Altas of Livebearers of the World. Four
were purchased for id purposes as well as for the BAP points to be
earned. Thumbing through the atlas, they were easily identified as
Poeciliopsis gracilis, one of the many livebearers found in the
streams flowing into both the Atlantic and Pacific in southern Mexico,
Guatemala, and Honduras. The males get to 1 3/4 inches in length while
the females can grow to 2-2 1/4 inches. The body coloration is
greenish with a slight blue iridescence. Their flanks have 4 to 6
black irregular spots thus the common name porthole
livebearer
. Even the babies have the spots at about two weeks of age
which makes it easy to distinguish them from other fry. All fins are
clear or have just the slightest hint of color. The species name
gracilis refers to the slender body shape, except for gravid females
of course! I keep all of my livebearers at temperatures in the mid to
high 70’s. Feedings consist of live baby and adult brine shrimp,
earthworm and spirulina flakes. I usually mix two or more kinds of
flakes together to insure variety. If kept well fed the adults don’t
seem to take any interest in eating the fry, which are about 1/4 inch
long at birth and have a preference for the surface. The females
produce a brood at about 28 days after fertilization by the males. So
far the maximum number of fry found has been eight. I suspect that
more are born but get picked off by the other fish in the tank. When
observed, the fry are caught and transferred to a five gallon rearing
tank choked with Java moss. I haven’t determined if the females can
store sperm for several broods like guppies do. Males constantly
pursue females and each other. This hyperactivity probably limits
their use as a dither fish for dwarf cichlids by they would be good
for larger ones that can’t eat them. If you want a lot of action in a
tank these hyperkinetic little fish will ad some zip to your tank.